const obj = {
  fun () {
    console.log('函数的简写形式，即省略了函数名')
  },
  hello: 'hello',
  world: 'world',
  ['hello' + 'world'] () {
    console.log('Hello World')
  }
}
obj.fun()
obj.helloworld()
console.log(Object.is('foo', 'foo')) // true
console.log(Object.is({}, {})) // false
console.log(Object.is(NaN, NaN)) // true
console.log(Object.is(+0, -0)) // false
// Object.assign()
const a = {
  a: 1,
  b: 2
}
const b = {
  a: 2,
  c: 3
}
const c = {
  c: 4,
  d: 5
}
console.log(Object.assign({}, a, b, c)) // { a: 2, b: 2, c: 4, d: 5 }
